[api] another events endpoint

apps/api/migrations/0012_event_room_index.sql

@@ -0,0 +1,8 @@
+-- The room_id index behind a room's event shelf (`GET /api/playerevents/v1/room/{roomId}`).
+-- Owned by the `api` worker; generated from src/events-db.ts (SCHEMA_DDL) — keep in sync.
+--
+-- The column itself has been on the `event` table since 0006; only the index is new. The
+-- club feed has had one since that migration and the room feed now reads the same way, so
+-- without this a room's shelf scans every event in the database.
+
+CREATE INDEX IF NOT EXISTS idx_event_room ON event (room_id);